Escherichia coli mutY gene encodes an adenine glycosylase active on G-A mispairs.
Journal Article (Journal Article)
Mutations in the mutY gene of Escherichia coli confer hypermutability reflecting G.C to T.A transversion mutations and result in a deficiency in methyl-independent G-A to G.C mismatch correction. In the present work, the mutY product has been purified to near homogeneity by virtue of its ability to restore G-A to G.C mismatch correction to cell-free extracts of a mutS mutY strain. The 36-kDa protein renders the strand containing the mispaired adenine labile to base-catalyzed cleavage and sensitive to cleavage by several apurinic/apyrimidinic-site endonucleases, with the sites of strand scission by both agents corresponding to the location of the mismatch. These findings indicate that MutY is a DNA glycosylase that hydrolyzes the glycosyl bond linking the mis-paired adenine to deoxyribose. MutY, a 5'-apurinic/apyrimidinic-site endonuclease, DNA polymerase I, and DNA ligase are sufficient to reconstitute MutY-dependent G-A to G.C repair in vitro.
- Au, KG; Clark, S; Miller, JH; Modrich, P
- November 1989
Volume / Issue
- 86 / 22
Start / End Page
- 8877 - 8881
Pubmed Central ID
International Standard Serial Number (ISSN)
Digital Object Identifier (DOI)
- United States